Sayyiduna Anas bin Malik (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) announced the deaths of the people of Mu'tah from the pulpit, then said: "Then Khalid bin al-Walid took up the banner, and he is one of the swords of Allah, the Mighty and Majestic."
Hadith Referenceالمعجم الكبير للطبراني / باب الخاء / 3785